Trampolin



Sept. 22, 1953 l.. v. GRlswoLD TRAMPOLINE Filed June l, 1950 INVENTOR. LAURENCE u GR/swoLo BY l ATTORNEYS Patented Sept. 22, 1953 UNITED STATES ATELNT OFFECE TRAMPOLIN Laurence V. Griswold, Cedar Rapids, Iowa Application June 1, 1950, Serial No. 165,541

3 Claims. 1

This invention relates generally to a yielding net construction. While this invention is particularly directed to a trampoline mat, it is also adaptable for use in life saving nets and the like. A trampoline is an apparatus used by acrobats which consists essentially of a mat mounted in a rigid frame by means of springs extending between the four edges of the mat and the correspending surrounding sides and e-nds of the rigid frame.

The present invention is an improvement in the mat construction of trampolines and like structures, so as to aiford the required resiliency and yet be suiiciently strong to withstand the severe stresses to which it is subjected in use.

One object of the present invention is to provide a trampoline mat of woven construction which reduces air resistance and thus provides greater iexibility and uniform response throughout.

A further object of the invention is to provide a woven trampoline mat which minimizes the danger of slipping and yet provides a non-abrasive surface to prevent friction burns to the user.

Another object of the invention is to provide a trampoline wherein the mat is uniformly and automatically tensioned by means of elastic cords securing the mat to the rigid trampoline frame.

A still further object of the invention is to provide a woven trampoline mat in which each strip comprising the woven web is adhesively secured to the perpendicularly interlaced strips at each contact area.

Another object of the invention is to provide a woven trampoline mat in which the ends of the web strips are firmly secured to the web structure so as to avoid the possibility of loose ends.

Another object of the invention is to provide a trampoline mat which is simple of construction, economical to manufacture and is durable and lasting.

Still another object of the invention is to provide a trampoline mat wherein the normally loose ends of the web structure are hidden from view on both sides of the mat so as to result in a neat appearance.

These and other objects and advantages of the invention will be apparent from the description which follows.

In the drawing:

Fig. l is a top plan view of the device mounted in a suitable frame ready for use.

Fig. 2 is a partial top plan view of the device on an enlarged scale.

Fig. 3 is a sectional View through section A-A of Fig. 2.

Fig. 4 is a sectional View through section EMB of Fig. 2.

Fig. 5 is an enlarged cross section through C-C of Fig. 2.

Fig. 6 is an enlarged cross section through D-D of Fig. 2.

Referring now to the drawing, showing a preferred embodiment of the invention in the form of a trampoline mat, the mat comprises a number of strips l5 of canvas or the like with additional transverse strips id interlaced to form a woven web indicated generally at I 2.

The strips l5 are secured to the: transverse strips lei by means of a suitable adhesive applied at the contact area I6. The adhesive is preferably a rubber-base cement as of liquid latex or the like which provides a permanent bond between the interlaced strips and yet affords stretch and resiliency to the web. In applying the adhesive between the contacting faces of the strips, the web bed is preferably placed in its taut, stretched condition, the adhesive being inserted between the contacting faces by means of a syringe.

An elastic ridge rope il passes through loops 2c formed by the various strips it and l5 at the outer edges of the web. The ridge rope pref erably comprises a cord of rubber or the like which in the form shown is encased in a protective sheath of braided textile strands. The use of a resilient ridge rope has the #advantage that as the webbing of the bed stretches in use, the ridge rope stretches a proportionate amount.

The ends I9 of the web-forming strips are doubled back to form the loops 29 and are adhesively secured between the second transverse strips i5 and the strips I4. The ends le are thus concealed to present a finished appearance. In addition, this feature of the invention aifords great er strength and durability to the web structure. The doubled-back ends i 9 are further secured to the strips M at every point from the loops 223 to the concealed ends i9 by means of a resilient adhesive.

The `web l2 is secured to a suitable rigid frame l U by a plurality of elastic cables i3. My Patent No. 2,534,019 issued December 12, 1950, discloses and claims a suitable type of trampoline frame. The cables I3 in the preferred form, have an inner core comprising a plurality of elastic strands 2| of rubber or the like covered by a sheath 22 of braided textile strands. The elastic cables i3 are looped around the ridge rope H, preferably between each of the web strips I6 around the perimeter of the web bed. The ends of the cables I3 are overlapped and firmly fastened together as by means of wire clips Il. The cables are further provided with eye hooks i8 which are secured to the frame l0.

It will be apparent that the present construction, as shown in Fig. 2, will, in its preferred form, be utilized around the entire periphery of the web bed. Thus, the transverse strips l5 as shown in Fig. 2 are constructed and arranged at their ends in the same manner as the ends i9 and 20 of the strips lfl and the strips lll thereby become transverse members at these ends of the web bed.

When the mat construction described above is mounted in a suitable frame I9, as by means of elastic cables i3, the web l2 is uniformly and tautly stretched in a substantially plane surface. In use, the performer jumps on the web structure. The resilient web and the elastic cables i3 allow the mat structure to stretch, thus permitting the performer to rebound to great heights. The woven web, having air spaces 23 between the strips, offers little air resistance and prevents billowing and the like. Also, the present construction prevents bogging down or pocketing when the web bed is not under a load and further permits an equal distribution of the load.

Thus it will be apparent that in its broader aspects, the present invention is generally directed to a web bed for trampolines and other rigid frames wherein the web bed comprises a plurality of crossed strips, generally interwoven, which strips are adhesively bonded to each other at their contacting faces, preferably by means of an elastic compound. In a further aspect, the present invention involves a trampoline or the like construction comprising a rigid outer support frame, an elastic; that is, resilient inner support frame, preferably a continuous rubber cable, a plurality oi elastic members, preferably rubber cables, for suspending the resilient inner frame to the rigid outer frame. A web bed comprising a plurality of crossed flat strips, preferably interwoven and adhesively bonded together at their contacting faces is secured to the resilient inner frame, preferably as by looping the ends of the strips around the inner frame and securing them to a web bed strip. the strip ends are elastieally bonded to and terminate between adjacent faces of a pair of crossing strips.

The woven web structure with the concealed ends I9 provides a safer, more durable construction, The resilient adhesive between the interlaced strips at l5 affords further stretch to the mat structure. While the invention has been described in the form of a trampoline mat, it will be understood that the invention, as disclosed and claimed, may be utilized in bed springs, life nets and the like, and it is intended to cover use of the invention in all such devices.

Preferably,

While the invention has been described and disclosed in the form of a preferred embodiment, it will be apparent that various departures may be made by those skilled in the art and it is intended that all such modifications shall be covered as one within the spirit and scope of the present invention as defined in the appended claims.

I claim:

1. In a trampoline and the like construction, a rigid outer support frame, a exible, stretchable inner support frame having substantial elasticity, a plurality of elastic members for attaching said inner frame to said outer frame, and a web bed supported by said inner frame, said web bed comprising a plurality of crossed strips, said strips being connected to said inner frame.

2. In a trampoline and the like construction, a rigid outer support frame, a flexible, stretchable inner support frame having substantial elasticity, a plurality of elastic members for attaching said inner frame to said outer frame, and a web bed supported by said inner frame, said web bed comprising a plurality of inter-woven strips bonded to each other at their contacting faces by means of an elastic adhesive, said strips being connected to said inner frame.

3. In a, trampoline and the like construction, a rigid outer support frame, a flexible, stretchable inner support frame having substantial elasticity, a plurality of elastic members for attaching said inner frame to said outer frame, and a web bed comprising a plurality of cross strips, the ends of said strips being looped around said inner frame and eing secured to a plurality of outer cross strips secured transversely to the rst named cross strips, said ends being bonded to and terminated between adjacent faces of a pair of crossing strips.

LAURENCE V. GRISWOLD.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,881 Curtiss Dec. 12, 1842 171,212 Buckley Dec. 21, 1875 1,621,841 Johnston et al Mar. 22, 1927 1,737,815 Warren Dec. 3, 1929 1,888,084 Howard et al Nov. 15., 1932 1,906,233 Leigh May 2, 1933 1,918,761 Kronheim July 18, 1933 1,925,516 Beckmann Sept. 5, 1933 2,226,606 Giles Dec. 3l, 1940 2,370,990 Nissen Mar. 6, 1945 2,534,019 Griswold Dec. 12, 1950 FOREIGN PATENTS Number Country Date 507,210 Great Britain June 8, 1939 605,282 Germany Nov. 28, 1934 

